Rules are identical for all police agencies but on-the-spot interpretation of those rules could mean the difference between life and death.

Recently, six of seven NJ Justices ruled police had no right to enter the home of a man whose landlord hadn’t seen him in weeks and whose neighbors said his car hadn’t been moved and mail was piling up. When the landlord asked them to check on his “good tenant,” police agreed there was reason for concern and entered his apartment.

They found he was fine, except a bit spaced out by all the marijuana they say he was stockpiling. So they arrested him.

The AG defended their actions arguing that police entered his home in their role as “community caretakers,” but the six justices disagreed. They threw out the criminal charge, saying the Emergency Aid Doctrine didn’t apply because no one had reason to believe the tenant needed help. They said there was no “objectively reasonable basis for believing an occupant may be seriously injured or imminently threatened with such injury.” That’s the standard set by the U.S. Supreme Court in an Arizona case 10 years ago.

But the definition of “objectively reasonable” is somewhat subjective. Suppose it was Grandma whose landlord was worried. Should police have made sure she was OK?

Courts agree police have a degree of responsibility to protect the public that includes checking on their welfare in an emergency. When flames are bursting through the windows or neighbors see an armed intruder, the danger is obvious. Other scenarios, not so much.

I talked with several retired high-ranking police officers and wasn’t surprised to learn each would have handled the situation differently.

One cited a textbook that read, “The business of policemen and firemen is to act, not to speculate or mediate on whether the report is correct.” He would have entered the home. Another said unless there is clear evidence the dweller had a potentially life-threatening condition, such as advanced age or serious illness, police should not invade privacy. He said the occupant could have been away or simply avoiding the world for a while and had a right to be left in peace.

A third noted EMTs never need a warrant to go anywhere someone could be in distress and cops often walk in right alongside them. Domestic violence laws require police to respond to any premises from which a 911 call was placed, even if it ended in a hang-up.

If officers enter private property without a warrant -- emergency or not -- they may not search for anything other than the worried-about person. However, once inside they can make arrests based on “evidence in plain view.”

Precedent-setting court rulings all resulted from police spotting drugs or weapons in homes of people who may or may not have been in actual danger. Rulings were based chiefly on the evidence of danger, not the evidence in the criminal case itself. No genuine danger, no admissible evidence.

A person could be wallowing in welcome isolation, engaging in criminal activity, or gasping for air. It will always be hard to tell from outside.

Justice officials are right to be careful an “emergency” never becomes a pretense to search private property without due cause and legitimate papers. But rules shouldn’t require help to remain outside when a life could be endangered. Perhaps it's time for experts and some regular citizens to sit down together and hash out some what-ifs to better define “emergency” and set some clear, compassionate and common-sense rules about criminal prosecutions based on entries that may be warrantless but not unwarranted.